Even in states with the longest school days, children stay in school for only seven hours. That falls short of standard eight-hour workdays plus commuting time.

The mismatch between workdays and school days makes synchronizing work and family schedules extremely difficult. It also means many Americans are paying for caregivers before and after school. Others rely on relatives and friends.

We found that mothers are more likely to work part-time in communities where school days are shorter. As school days lengthen, the odds of mothers in that community working full-time rise.

Interestingly, we found that many states where child care costs more also tend to have shorter school days. That means parents can face more than one larger-than-average child care burden, depending on where they live.

All states are not equal

It surprised us to see that some states with shorter school days and more expensive child care happen to have progressive political leadership. For example, the nearly 40 million people living in California have some of the highest average child care costs, shortest school days and lowest rates of maternal full-time employment in the nation.

In contrast, we found that Nebraska has some of the most affordable child care, longest school days and highest rates of maternal employment. In Nebraska, an average of 60% of mothers work full-time, compared to 40% in California.